Method of moth proofing woolen goods



standardized testing conditions considerably lower than the amount of0.8 mg. per larvae which is indicated as an acceptable limit for theattack of moth larvae on an entirely antimoth proofed woollen fabric.

In spite of deficient knowledge about the nature of the bonds betweenthe silico fluorides and the wool it appears that it is not a questionof genuine valence combinations, but a question of coordinative bindingforces between the silico iluoride complex and the wool substance. Thesebinding forces will be fully developed only when the amino groups of thewool substance are entirely free from acid residues, and consequently itis obvious that they will in the first place act between these aminogroups and the Silico fluorides. A blocking of the amino groups byanions from dye-stuffs to a normal, i. e. to a relatively limited,extent, does not seem to disturb the binding forces, but such adisturbance` appears only when blocking occurs by acid anions whichcause a decrease of the pl-l value in the surface layer of the fibres.

The susceptibility of the nbre material to acid is very great. Thus,experiments have shown that woollen material which has been subjected totreatment in an acid bath (dye bath), then carefully rinsed in water andfurther treated in a buffered solution having a pH value of 6, could notnx the silico uorides in a subsequent treatment in a solution of silicoiluoride having a normal pH value of 4.0 to 4.5, so that a washingfastness was obtained. Thus, in all such cases where acid residues arepresent in the wool a real neutralization with a small excess of akalimust be carried out to obtain a xation resistant to washing. If thetreatment with silico fluoride is carried out on a non-neutralizedmaterial a normal absorption of silico fluoride in the wool (0A-0.5%iiuorine) will generally be obtained, but the nxation will not begenuine and most of the fluorine will be removed upon ordinary washing.Neutralization with ammonium is to be preferred as it will then beeasier to remove the excess of alkali by rinsing than if soda is used.

y Besides being resistant to alkaline washing the bond between a neutralwool and silico fluoride is to a certain extent intact also against theaction of a boiling acid bath. If the concentration of the acid isincreased to such an extent that the pH value falls below 3.0, the bondwill gradually break up, so that the fluorine is removed. This meansthat in such cases where it is a question of dyeing wool free from acidin a dye bath not containing great quantities of acid (acid dyeing orchrom dyeing) thetreatment with silico fluoride may take place justbefore the dyeing.

It has also been proved that a neutral wool can be treated in a Silicofluoride bath to which considerable amounts of acid have been added anda resistant fixation of the silico fluoride in they wool may beobtained. In this case it appears that the silico fluoride is bound tothe wool so quickly that a reaction betweenthe acid and the amino groupsof the wool will not have time to occur to any noticeable degree untilthe silico fluorides are already xed. Thus, when it is the question ofdyeing wool free from acid in a dye bath containing small quantities ofacid (1.0- 2.0% of the weight of the wool) it is in practice possible tocarry out the treatment with silico iiuoride at the same time as thedyeing. When on the other hand the dyeing bath contains greater amountsof acid (neulan-dyeing) the treatment with silico fluoride can becarried out complete fixation will take place.

only lafter the dyeing and must then be preceded by a carefulneutralization. In this connection it will be observed that a so-calledcarbonization after a treatment with silico fluoride entirely destroysthe anti-moth protecting effect in that the silico fluoride is destroyedand decomposed by the concentrated sulphuric acid which in this processacts on the wool during the drying. After neutralization of the acidwoollen material it is, however, possible to treat the materialsuccessfully with silico fluoride in a normal way.

It has furthermore been found that the fixation effect is furtherimproved if the wool after the treatment with silico iiuoride is treatedin a f. bath containing ordinary soaps of fatty acids.

Certainly, the fixation effect obtained by the method described above issunicient to prevent the silico fluorides from being removed by a simplerinsing Yin water, and as soon as the cloth is washed in a soap solutionthe above-mentioned If, however, the washings are instead carried out bymeans of synthetic washing agents it has been shown that the silicouorides are extracted to a large extent, and it may therefore benecessary to carry out a complete fixation of the silico fluoride in thefactory by a simple treatment in soap solution. After such treatment thefollowing washings in synthetic washing agents will cause no noticeable.f extraction of fluoride.

Regarding the nature of the fixation achieved in this way nothing can besaid with certainty but conditions are likely to be the following. Onlya part of the amino groups of the wool are responsible for the genuinefixation of the silico nuorides. These amino groups are evidently veryeasily blocked by acids which is why the wool must be neutralized beforethe Silico uoride treatment, which should be carried out at a pH valueabout corresponding to the natur-al pH value of the acid ammonium silicofluoride solutions. If these amino groups are free they will in thefirst place form salts with the silico fiuorides. In the subsequenttreatment with soap small amounts of fatty acids are likely to beprecipitated as the wool is acid. On account of special relationsbetween adjacent p olar groups the precipitated fatty acids willevidently enter into some complex formation between the wool and thesilico iiuorides. The cloth thus impregnated with silico iiuoride andtreated with soap may then be subjected to repeated washings in alkalinebaths as well as in baths containing diiferent kinds of syntheticwashing agents without the silico fluoride being removed but to thelimit (about 0.20% nuorine based on the weight of the wool) determinedby the active groups in the f wool.

Example 1 A strip of white woollen fabric weighing 30 g. was dyed byboiling for 2 hours with 3% neulandyestui (neulan red GRE) in a dye bathcontaining 8% sulphuric acid and 10% crystallized sodium sulphate,calculated on the weight of the fabric. The fabric was rinsed in flowingwater during 30 min. and then treated for 10 min. at room temperature ina solution containing 0.05-normal ammonia at a ratio of 1:25 betweenmaterial and liquid. The material was then rinsed for 5 min. in flowingwater and treated for 20 min. at a temperature of about 25 C. in asolution containing Y3% ammonium silico uoride, calculated on the weightof the material at a bath ratio of 1:25. Finally rinsing.

l in flowing water` for 1i) min. and drying took place. Y

For determination of the washing fastness `of the impregnation, samplesVof 'the impregnated fabric were washed l, 2 'and 4 times respectivelyin solution containing 5 fg.. soap per liter. The treatment tookplaeeduring naif an'hoiir at a bath `ratio of 1:50 .and a twmerature of40 C'. after each washing the fabric was rinsed i3 for 2 min. each time:in distilled water at 10 C. l

In. biological with moth larvae aladin analyzing the amount of iluminein the fabric the 'multe in the following 'tableware obtained:

.A :si-.nip of chromium-dyed and carbonized but not fully neutralizedwoolen fabric containing 1.2%v sulphmii'c acid was treated for 15 min.at room temperature in a 0.05-normal solution of soda @at sa bath ratioof 12:25. "The :fabric was rinsed in flowing water for l5 .minar-1dtreated at 25 C. for 20 Imin. at a bath ratio of 1:25 in a solutioncontaining 3% ammonium Silico uoride, calculated on the weight of thefabric. ."Finally, the fabric was rinsed in owingwater for '10 min.

in biological testing with moth larvae and in analyzing the amount offluorine the results in the following table were obtained. The washingsof the samples were carried out as in Example 1:

. Example 4 20 .g-"White uncrded wodlV dye'dbygboiif Ilng for l hourwith 3% Azorhodin 2G in 'a dye bath containing 3% Vsulpl-iuric acid and10% crystallized sodium sulphate, calculated on the weight of the wool.The wool was then rinsed in 'owing water for 30 min. and treated at roomtemperature for min. in a solution containing ll.05normal .ammonia at abath ratio of 1:50. The wool was rinsed for 10 min. in :ilowing waterand treated for 1'0 min. ata temperature of about 25 C. in a solutioncontaining 3% ammonium slico iiuoride, .calculated on 4the weight ofvthe Wool, at a bath ratio of 1:50. Finally, rinsing in flowing waterfor 10 min. and drying took place.

In biological testing with moth 'larvae and in analyzing the .amount .offluorine the results in the .followingy table` wem obtained. Thewashings of the lsamples ywere carried out .in Ex ample 1 Example '5 .Awhite woollen fabric was neutralized with ammonia .and rinsed in flowingwater. The fab? ric was then impregnated at `a temperature .of .25 C..and a hath-ratio of 1:25 .01220 min. in an ammonium silice fluoridesolution of afaryingom centration. Finally, the fabric was rinsed inilowing water of room temperature for min. The onsump- Percent resultsare given in the following table. The Fahne 011m 1g-f Hummel t0 amountvof silico fluoride is given in `percentage larvae the fabric 1 Y.

of .weight of fthe fabric.

`lllmvhasdhed ggg C' as e once Y ontent oiammoniirm silico Washed twice0.56 0.20 uoriden the bathin Unwashed Washed Washed Washeditimes 0.560.20 percent weight Habra once twice 0.25v `0.19l 0.08 Example 3 0.32V`0.21 n.21 0. 39 0. 21 0. 20 A strip of undyed but carbonized and notfully 0.40 0:21- 0.121 neutralized woollen fabric was treated for 15min. l 143 0-21 0-20 at room temperature in a 0.05-normal ammoniasolution at a bath ratio of 1:25. The fabric was then rinsed in flowingwater for 15 min. and treated at C. for 20 min. at a bath ratio of 1:25in a solution containing 3% ammonium silico fluoride, calculated on theweight of the fabric. 3% sulphuric acid, 10% crystallized sodiumsulphate and 3% Azorhodin 2G was then added to the ammonium silicoiluoride bath, whereupon dyeing took place by increasing the temperatureto 100% C. and boiling for 1 hour.

Finally, the fabric was rinsed in owing water for 1A; hour. Inbiological testing with moth larvae and in analyzing the amount offluorine the results in the following table were obtained. The washingsof the samples were carried out as in Example 1:

The results show in the first place that it is sufdcient to use as smallquantity of silico nuoride as 1% of weight of the fabric. It isfurthermore evident that the wool is capable of binding about 0.20%iluorine disregarding the concentration of silico uoride in the bath.This is vigorous proof of the theory that a well neutralized wool willto a certain extent strongly bind silico uoride and that the wool showscertain spots at which linkage may take place.

Example 6 Uncolored woolen cloth was treated with 0.05-n ammoniasolution for 30 min., whereupon the cloth was rinsed in flowing waterfor 15 min. and. then treated in a silico fluoride bath. The cloth wasthen divided into three parts which were further treated as follows:

1. One sample was washed four times (each time for 30 min.) at 40 C. ina solution containlng 5 g./1. soap akes.

2. One sample was washed four times in the same way in a solutioncontaining 2 g./1. lauryl alcohol sulphonate. Y

3. One sample was first treated for 15 min. at

7 40 C. in a solution containing 3 g./l. soap, rinsed and washed fourtimes in a solution containing 2 g./l. lauryl alcohol sulphonate. Theresults appear in the following table:

Sample Treatment Unwashed 0. 42 1 Washed once in soap solution- 0. 22Washed twice in soap solution..- 0. 20 Washed four times in soap solutlo0, 2l) Unwashed (l. 42 Washed once in lauryl alcohol sulphonate. l). 142 Washed twice in lauryl alcohol sulphonate 0. l0 Wasled -i times inlauryl alcohol sulpho- 0. 09

na e. v Washed once in soap solution (l. 25 Washed once in laurylalcohol sulphonatc 0. 22 3 Washed twice in lam-yl alcohol sulplionateA0. 2l Washed 4 times in lauryl alcohol sulplio- 0. 2i

nate

Test No. 3 proves thatabout 0.20% iiuorine is fixed to the wool by thesoap treatment, so that thereafter extraction by washing does not occur.

Example 7 A colored Woollen cloth was neutralized as in Example withammonia, rinsed in flowing water for l5 min. and treated with silicouoride. The cloth was divided into two parts, one of which was treatedat room temperature for 30 min. in a solution containing 5 g./l. soapand then rinsed, While the other one was not subjected to suchtreatment. Both samples were put in distilied water, which was changedevery day. Analysis of the iluorine content in each piece of cloth wasmade after different periods of extraction in distilled Water. Theresults appear in the following table:

Percent lluorine Time in water Not treated Treated with soap with soapThe table shows that a` good iixation is achieved by the treatment withsoap.

I claim:

l. A method of moth proofing woolen goods containing acid residuesdeposited in said goods during the manufacture thereof, which comprisestreating the woolen goods in a Water solution containing an alkalineneutralizing agent in an amount in excess of that required to'neutralizeall of said acid residues in the woolen goods. rinsing the Wolen goodsin water to remove the neutralized acid residues, immersing the Wool ina water solution containing a Water-soluble silico fluoride in an amountcorresponding to at least about l by weight of the goods, and drying thewoolen goods, whereby said uoride becomes rmly fixed to the bers of saidwoolen goods and is resistant to displacement therefrom upon repeatedwashing. Y

2. A method of moth proofing woolen goods as defined in claim l, furthercomprising the step of immersing the woolen goods after immersion in thewater solution of the Silico iiuoride in a water' solution containing awater-soluble fatty acid soap.

- ERIK BIRGER ERI-KSSON.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,634,790 Minaei July 5, 1927 1,682,975 Meckbach Sept. 4, 19231,914,059 White June 13, 1933

1. A METHOD OF MOTH PROOFING WOOLEN GOODS CONTAINING ACID RESIDUESDEPOSITED IN SAID GOODS DURING THE MANUFACTURE THEREOF, WHICH COMPRISESTREATING THE WOOLEN GOODS IN A WATER SOLUTION CONTAINING AN ALKALINENEUTRALIZING AGENT IN AN AMOUNT IN EXCESS OF THAT REQUIRED TO NEUTRALIZEALL OF SAID ACID RESIDUES IN THE WOOLEN GOODS, RINSING THE WOOLEN GOODSIN WATER TO REMOVE THE NEUTRALIZED ACID RESIDUES, IMMERISING THE WOOL INA WATER SOLUTION CONTAINING A WATER-SOLUBLE SILICO FLUORIDE IN AN AMOUNTCORRESPONDING TO AT LEAST ABOUT 1% BY WEIGHT OF THE GOODS, AND DRYINGTHE WOOLEN GOODS, WHEREBY SAID FLUORIDE BECOMES FIRMLY FIXED TO THEFIBERS OF SAID WOOLEN GOODS AND IS RESISTANT TO DISPLACEMENT THEREFROMUPON REPEATED WASHING.